IESCO Bill Calculator: Check Your Estimated Electricity Bill
You punch your units into an IESCO bill calculator and the number rarely matches your printed bill — this guide shows you why. Get an instant estimate using current IESCO slab rates, then see exactly how FPA, GST, and fixed charges account for the gap between the calculator and your real bill.
You punch your units into an iesco bill calculator, get a number, then open your actual bill and the two don’t match. That mismatch is the single most common complaint I hear from IESCO consumers, and it’s rarely because the calculator is broken — it’s because most calculators only do half the math.
The IESCO bill calculator estimates a residential customer’s monthly electricity charge by applying NEPRA’s slab-based tariff to total units consumed, then adding fixed charges, Fuel Price Adjustment (FPA), and GST. It’s an estimate — your final printed bill can vary slightly month to month because FPA changes and isn’t something a simple units-times-rate tool ever accounts for.
That’s really the whole story of this page. We’ll give you a working calculator, then walk through exactly why the number it produces sometimes drifts from what IESCO actually bills you — so you’re not left second-guessing either number.
Calculate Your Estimated IESCO Bill
IESCO Bill Calculator
NEPRA tariff: S.R.O 279(I)/2026 · Feb 2026 · estimates exclude FPA
Estimate only. Your official bill also carries that month’s Fuel Price Adjustment (FPA), any arrears, and fixed charges for un-protected connections — so the printed figure will differ. The structure above matches how IESCO builds the bill.
Enter your monthly units below and the tool will apply the current IESCO slab rate for your consumption band, along with the applicable fixed charge. FPA is shown as a placeholder line since it’s revised monthly by NEPRA and isn’t fixed — more on that below.
How Is My IESCO Bill Calculated? (Formula Breakdown)
Your IESCO bill is built in layers, not a single multiplication. Start with your total units for the billing month, apply the per-unit rate for whichever slab those units fall into, then add the fixed monthly charge tied to your sanctioned load, then the Fuel Price Adjustment, then GST, then the PTV fee. Add those five pieces together and you get your total.
Here’s the sequence in order:
- Units consumed — read from your meter, shown on your bill as the difference between current and previous readings.
- Slab-based variable charge — your units multiplied by the rate that applies to your consumption band (explained fully in the table below).
- Fixed monthly charge — a Rs./kW/month charge tied to your sanctioned load, separate from how much electricity you actually use.
- Fuel Price Adjustment (FPA) — added or subtracted based on the actual fuel cost NEPRA calculates for that billing month. This is the line item that shifts the most from bill to bill.
- GST and PTV fee — sales tax and the television license fee, both added on top of the energy charge.
I’ve tested this against real printed IESCO bills rather than just the tariff notification PDF, and the gap between a simple calculator and your actual bill almost always comes down to steps 4 and 5 — not a wrong slab rate.
IESCO Unit Rates & Tariff Slabs (2026)
These rates reflect IESCO’s officially published A-1 Residential tariff under S.R.O No. 279(I)/2026, notified in February 2026. IESCO tariffs are revised periodically by NEPRA, so treat this table as your reference point and always confirm against your latest printed bill.
Consumer Slab-Wise Electricity Tariff & Charges
Detailed breakdown of consumption bands, unit rates, and fixed monthly charges
| Consumer Category | Consumption Band | Rate (Rs./unit) | Fixed Charge (Rs./kW/month) |
|---|---|---|---|
| Protected — Life Line | Up to 50 units | 3.95 | — |
| Protected — Life Line | 01–100 units | 7.74 | — |
| Protected | 001–100 units | 10.54 | 200 |
| Protected | 101–200 units | 13.01 | 300 |
| Unprotected | 1–100 units | 22.44 | 275 |
| Unprotected | 101–200 units | 28.91 | 300 |
| Unprotected | 201–300 units | 33.10 | 350 |
| Unprotected | 301–400 units | 36.46 | 400 |
| Unprotected | 401–500 units | 38.95 | 500 |
| Unprotected | 501–600 units | 40.22 | 675 |
| Unprotected | 601–700 units | 41.85 | 675 |
| Unprotected | Above 700 units | 47.20 | 675 |
This page covers residential (A-1) tariff calculation only. If you’re running a shop, an office, or an industrial connection, the commercial and industrial slabs are structured differently — our IESCO tariff rate guide covers the full A-2, B, and C categories in detail.
Why Your Manual Calculation Might Not Match Your Bill
This is the part most calculator pages skip entirely, and it’s the reason I built this section the way I did. Three things cause the gap between your own math and IESCO’s printed total.
Fuel Price Adjustment changes every month. FPA isn’t baked into the slab rate — NEPRA calculates it separately based on actual fuel costs for that billing cycle, and it can add a noticeable amount to your bill in a month when fuel prices spike, or subtract from it when they ease. A calculator that doesn’t ask you for the current FPA figure is giving you last month’s picture, not this month’s.
Slab-boundary rounding catches people off guard. If your consumption sits right at the edge of a slab — say 199 versus 201 units — you can end up in a different rate band than you expected, and the fixed charge tied to that band changes too. It’s not a bug in the calculator; it’s how the tariff is structured.
GST applies differently depending on your total. The tax portion isn’t a flat percentage across every bill — it can shift for consumers crossing certain consumption thresholds, similar to how the 500-unit mark matters elsewhere in the tariff. Your printed bill shows the exact GST line item applied to your account, and that’s worth checking against rather than assuming a fixed rate.
If your calculated number and your printed bill are close but not identical, this is almost always why — not a wrong slab rate.
Understanding IESCO Peak Hours (Time-of-Use Billing)
Here’s something most people don’t realize until they’ve called the IESCO helpline confused about a bill: peak-hour pricing doesn’t apply to every household. Under IESCO’s tariff, Time-of-Use (TOU) billing only kicks in for connections with a sanctioned load of 5 kW or above. If your home has a standard connection below that threshold, you’re billed at the flat slab rate regardless of what time of day you used electricity.
For TOU consumers, IESCO’s officially notified rates are Rs. 46.85/unit during peak hours and Rs. 34.53/unit off-peak, with a fixed charge of Rs. 675/kW/month. Peak hours generally fall in the evening — commonly cited as running between 6 PM and 10 PM, with some seasonal shift — but the exact window on your account is worth confirming against your own bill or IESCO’s notification, since TOU timings are set separately from the unit rate itself.
Do I pay peak hour rates if I don’t have a TOU meter? No. If your IESCO connection is on a standard meter rather than a Time-of-Use meter, you’re billed at the flat slab rate for your total monthly units regardless of when you used electricity. TOU billing only applies to connections at or above the 5kW sanctioned-load threshold, and it requires a TOU-capable meter to actually separate peak from off-peak consumption.
GST, FPA & Other Charges Explained
Your bill has line items beyond the raw energy charge, and none of them are optional or negotiable — they’re set by regulation, not by IESCO itself.
Understanding Your Electricity Bill Charges
| Charge | What It Is |
|---|---|
| FPA (Fuel Price Adjustment) | A monthly adjustment reflecting the real cost of fuel used to generate power that month, set by NEPRA and applied uniformly across the tariff. |
| GST | Sales tax applied to the energy charge under the standard federal sales tax framework, with the applied percentage varying by consumer category and consumption level. |
| PTV Fee | A fixed television license fee added to residential bills regardless of usage. |
| Fixed/Meter Rent Charge | A Rs./kW/month charge tied to your sanctioned load, billed whether or not you use electricity that month. |
| Minimum Monthly Charge | Rs. 75 (single-phase) or Rs. 150 (three-phase) — applies as a floor even on a zero-consumption bill. |
Worked Example: Calculating a 350-Unit IESCO Bill
Let’s walk through an unprotected residential consumer using 350 units in a month, on a standard (non-TOU) connection.
- Units consumed: 350 units for the month.
- Applicable slab: 350 units falls in the 301–400 unit band, billed at Rs. 36.46/unit.
- Variable charge: 350 × 36.46 = Rs. 12,761.
- Fixed charge: Rs. 400/kW/month for this slab, applied per your sanctioned load.
- FPA: Added separately based on that month’s NEPRA-notified adjustment — this is why your printed total won’t match a calculation that skips this step.
- GST and PTV fee: Added on top of the energy charge, shown as separate line items on the bill.
- Total: Variable charge + fixed charge + FPA + GST + PTV fee = your final bill amount.
Notice that steps 5 and 6 are exactly where a bare-bones calculator falls short — the variable and fixed charges alone (roughly Rs. 13,000+ in this example) are only part of the real total. This is also the point where I’d recommend checking your figure against your actual bill through IESCO’s bill check portal rather than trusting an estimate alone if you’re trying to budget precisely.
Net Metering and Your Bill Calculation
If you have solar panels and a net-metered or net-billed connection, your bill calculation works differently from the examples above. Instead of simply billing your total units consumed, IESCO nets your imported units against what your system exported to the grid — and as of the recent shift from net metering to net billing under NEPRA’s updated Prosumer Regulations, exported units are credited at a separate export rate rather than at the same rate you pay for imported electricity.
Practically, this means a solar household’s bill calculator has to account for two different rates — one for what you draw from the grid, one for what you send back — rather than a single slab rate applied to total consumption. This page’s calculator is built for standard consumption billing; if you’re on net metering, treat the numbers here as a starting point for your grid-import portion only, not your full net position.
Frequently Asked Questions
Your bill is built by multiplying your monthly units by the slab rate for your consumption band, then adding the fixed monthly charge tied to your sanctioned load, the Fuel Price Adjustment set by NEPRA, GST, and the PTV fee. Each of these is a separate line item on your printed bill.
It depends on your consumer category and consumption band. Protected life-line consumers using up to 50 units pay Rs. 3.95/unit, while unprotected consumers using above 700 units pay Rs. 47.20/unit. The full slab table above shows every band in between.
Peak hours generally fall in the evening, commonly cited as 6 PM to 10 PM with some seasonal variation. This only matters if your connection has a sanctioned load of 5 kW or above and a Time-of-Use meter — standard connections are billed at the flat slab rate regardless of time of use.
No. Only consumers with a 5 kW or higher sanctioned load and a TOU-capable meter are billed separately for peak and off-peak consumption. Everyone else pays the standard slab rate.
The most common reason is Fuel Price Adjustment, which changes monthly and isn’t fixed into a simple calculator. Slab-boundary rounding and GST variation can also account for smaller differences — see the section above on why manual calculations often don’t match the printed bill.
FPA stands for Fuel Price Adjustment. It’s a monthly charge set by NEPRA that reflects the actual cost of fuel used to generate electricity that billing cycle, applied on top of your base energy charge.
GST is applied to the energy charge under the standard federal sales tax framework, and the applicable rate can vary by consumer category and consumption level. Your printed bill shows the exact GST figure charged to your account for that month.
Protected consumers are a specific category assigned by IESCO, generally tied to lower consumption bands, that receive a reduced per-unit rate compared to unprotected consumers using the same number of units. Your bill or consumer profile will show which category applies to you.
Yes. Net-metered or net-billed solar connections are billed on the difference between what you import from the grid and what you export, with exports credited at a separate rate rather than the standard import tariff — see the net metering section above.
NEPRA reviews and notifies IESCO’s tariff periodically, sometimes quarterly and sometimes as circumstances require. The current rates in this article reflect S.R.O No. 279(I)/2026, notified in February 2026 — always confirm against your latest bill if you suspect a rate change has occurred.
If your calculated estimate is off by more than the FPA and GST factors explain, it’s worth checking your account directly rather than assuming the calculator is wrong — you can pull your actual bill through our IESCO bill check page, pay it directly through IESCO online bill payment, or if you spot a genuine billing error, IESCO’s complaint helpline is the right next step rather than disputing it through the calculator alone.